Known in the art are a great number of materials on the basis of compositions incorporating heat-resistant heterocyclic polymers.
However, in the preparation of such materials use is made of only final polymers. The starting monomers cannot be directly employed for the production of said materials, since during polymerization thereof certain by-products are formed (such as H.sub.2 O, CO.sub.2, NH.sub.3) which result in substantially impaired properties of the final materials. For this reason, for the purpose of attaining the best properties of the materials, first effected is the process of preparation of a polymer involving stages of synthesis, recovery and purification of the polymer, followed by processing of the thus-prepared polymer to a corresponding material. Said additional stages (i.e. synthesis, recovery and purification of the polymer) substantially complicate the process of manufacture of the final materials and render their manufacture more expensive; it is also necessary to have additional production areas. The process of treatment of the final heterocyclic polymers is accompanied by certain difficulties. While ensuring a high thermal and thermo-oxidative stability of polymeric chains, the aromatic nature of these polymers at the same time defines strong intermolecular effects. For this reason, in the case of heat-resistant heterocyclic polymers softening temperatures and, hence, temperatures of processing said polymers to final articles frequently approach destruction temperatures, i.e. within the range of from 350.degree. to 400.degree. C. At the same time, said difficulties may be overcome by the use of the starting reagents which react without liberation of any by-products. This enables elimination of said stages of synthesis, recovery and purification of polymers as separate technological processes, since the formation of a polymeric structure may occur simultaneously with the process of manufacture of the final material. Since the starting reagents feature a higher mobility than macromolecules based thereon and taking into account the fact that the process of formation of a heterocyclic polymeric structure is substantially completed at temperatures of less than 300.degree. C., the process of manufacture of the final articles in this case may be also performed at temperatures of below 300.degree. C. Reagents possessing such properties are bis-ortho-aminonitriles and bis-ortho-hydroxynitriles which, upon reaction with polyfunctional isocyanates, form heat-resistant polymers of a heterocyclic structure corresponding to the formulae: ##STR2## respectively, wherein R is selected from the group consisting of: ##STR3## wherein R.sup.2 is selected from the group consisting of an alkylene radical containing 1 to 4 carbon atoms. ##STR4## wherein R.sup.3 and R.sup.4 are selected from the group involving an alkyl radical containing 1 to 3 carbon atoms and an aryl radical; R' is selected from the group consisting of an alkylene radical containing 2 to 40 carbon atoms, ##STR5## wherein R.sup.5 is an alkyl radical containing 1 to 3 carbon atoms R.sup.6 is an alkylene radical containing 1 to 4 carbon atoms, ##STR6## wherein R.sup.7 and R.sup.8 are selected from the group consisting of an alkyl radical containing 1 to 3 carbon atoms and an aryl radical (cf. U.S. Pat. Nos. 3,657,186 and 3,674,749). The interaction of bis-ortho-aminonitriles and bis-ortho-hydroxynitriles with polyfunctional isocyanates is effected at a temperature within the range of from 150.degree. to 300.degree. C. over a period of from 1 hour to 24 hours.
However, as it has been demonstrated by appropriate tests, the materials produced directly from the above-mentioned reagents feature a high brittleness. During a lasting residence in the air at temperatures of about 300.degree. C. and over a substantial decrease in mechanical strength of said materials is observed, crasks are formed which frequently cause a complete break-down of the final materials.